[llvm] [IR] Reject a scalable byval argument in the verifier (PR #226170)

[Timur Baidusenov via llvm-commits]

================
@@ -1378,6 +1378,8 @@ Currently, only the following parameter attributes are defined:
     interpreted as a call to memcpy with the allocation size of the specified type,
     instead of loading from the pointee and storing back into the copy in the type.
     In particular, the padding between field types of a struct type is still copied.
+    The type must not be a scalable type, as the size of the copy has to be known
+    at compile time.
----------------
bai-tim wrote:

Thanks, applied the LangRef suggestion and reworded the description.

https://github.com/llvm/llvm-project/pull/226170